Changing 1-3 Speed gear on JM 284

I broke few of my transmission gear on my JM 284… Now i need to change them…

Now i'm in 1-3 speed gear changing procedure. I studied well my manual and it seems that i have to remove all the diferential and all other parts in the housing to remove the shaft that hold the 1-3 speed gear

It seem pretty complicated just to change a gear, can someone confirm me that information… and if you have some tips, it will be appreciated   

For those who want to know :

-to change transmission gear, you need to split the tractor in half by removing the bolts in the center frame

-from here you can remove reverse gear easily, all the gear forks and sliding shaft (for the forks) (note : there are some balls to hold the forks shafts : dont lose them) 

-remove the bearing bracket, remove the snap rings and remove the top shaft : you have to remove the inner shaft to change the gear :

(the inner shaft joins to the pto shaft but you can remove it without removing the hydraulic oil tank ) 

-Now the tricky part : for 1-3 speed gear ; it seems that you have to remove the hydraulic oil tank than the rear wheels than rear axle and differential to remove the 1-3 gear shaft … 

ONE ADVICE : DON'T BREAK THE 1-3 SPEED GEAR